Analysis of nitrite in adulterated urine samples by capillary electrophoresis

A simple method for analyzing nitrite in urine has been developed to confirm and quantify the amount of nitrite in potentially adulterated urine samples. The method involved separation of nitrite by capillary electrophoresis and direct UV detection at 214 nm. Separation was performed using a bare fused silica capillary and a 25 mM phosphate run buffer at a pH of 7.5. Sample preparation consisted of diluting the urine samples 1:20 with run buffer and internal standard, and centrifuging for 5 min at 2500 rpm. The sample was hydrodynamically injected, then separated using -25 kV with the column maintained at 35 degrees C. The method had upper and lower limits of linearity of 1500 and 80 microg/mL nitrite, respectively, and a limit of detection of 20 microg/mL. The method was evaluated using the National Committee for Clinical Laboratory Standards (NCCLS) protocol (Document EP10-A2), and validated using controls, standards, and authentic urine samples. Ten anions, ClO-, CrO4(-2), NO3-, HCO3-, I-, CH3COO-, F-, SO4-, S2O8(-2), and Cl-, were tested for potential interference with the assay. Interferences with quantitation were noted for only CrO4(-2) and S2O8(-2). High concentrations of Cl- interfered with the chromatography. The method had acceptable accuracy, precision, and specificity.     

Identification of ascorbic acid and its degradation products in black powder substitutes

Low explosives such as smokeless powder, black powder, and black powder substitutes have been used in illicit pipe bombings throughout the United States. Some of the newer black powder substitutes are formulated with ascorbic acid, which gradually decomposes as the powder ages, making it difficult if not impossible for the forensic chemist to identify it by traditional bulk techniques. A sensitive method for the identification of residual levels of ascorbic acid in black powder substitutes is presented. Powder samples are extracted with a mixture of acetonitrile and bis(trimethylsilyl)acetamide (BSA), which converts carboxylic acid and alcohol functional groups to trimethylsilyl esters and ethers, respectively. Samples are then analyzed by gas chromatography-mass spectrometry (GC-MS). Results have shown that trace amounts of ascorbic acid can be identified at detection limits that are well below those for traditional bulk techniques. Degradation products for ascorbic acid (hydroxylated carboxylic acids, furanones, and lactones) can also be detected.     

The morphological specificity of relaxation of cardiomyocytes and their value in forensic medical diagnostics

The morphological specificity of different conditions of cardiomyocytes was studied in myocardia of 50 cadavers of men who died of a variety of reasons. All conditions, except for the normal relaxation of cardipmyocytes, were found to result from damages in the contractive apparatus. Morphological variations of relaxation of cardiomyocytes are described.     

The forensic medical diagnosis of intoxication of alcohol surrogates by morphological findings

The pathomorphology of intoxication of alcohol surrogates is described. A high frequency rate of DIC-syndrome is shown for the condition. A majority of thrombi accumulates at places with the highest concentrations of toxic substances as well as at those places, through which poisoning substances are brought out of the body, i.e. in the liver (since toxic substances are introduced perorally) and kidneys. Thrombi were detected in all internals, including the brain, in lethal intoxication. The immediate toxic effect from methanol and from higher spirits can matter in the genesis of changes, including acute swelling and chromatolysis with subsequent cell death. Exclusively cerebral or coagulopathic-cerebral types of thanatogenesis were registered in studied case of intoxication.     

Significance of changes in the myocardium for the forensic-medical diagnosis of death as a result of alcoholic cardiomyopathy

Significance, of the weight and dimensions of heart as well as of fat dystrophy of cardiomyocytes and of the related detection methods is demonstrated for the diagnosis of alcoholic cardiomyopathy (ACMP). When such patients die in a state of alcoholic intoxication, the diagnosis should be death of acute alcoholic intoxication. Lethality of ACMP can be diagnosed only in those who die in the sober condition or with an insignificant level of alcohol.     

Polymorphism of the central region of D-loop of mitochondrial DNA and personality identification by forensic medicine methods

Polymorphism of mDNA D-loop central region (CR), positions 16366-0072) was studied versus hypervariable sections (HVS1), positions 16024-16365, and HVS2, positions 00073-00340, for a sample of 71 residents of the Russian Federation. Ten polymorphic positions with 56 nucleotide substitutions, 55 of which are transitions, were detect in the CR section; no insertions or deletions were found there. It was proven as possible to use the mDNA CR locus as an additional identification marker in the forensic-expert of the mDNA control region. The probability of random coincidence (RC) of haplotypes in joint typing of HVS1, HVS2 and CR made 0.0208, which is 1.4-fold less versus the same parameter for haplotypes HVS1/HVS2 (RC = 0.0284).     

Determination of group affiliation of isolated spermatozoa after separation from squamous epithelium cells

Outlined in the paper are outlooks for determining a group affiliation of sperm in traces, left in material evidence, within forensic biological expertise. A technique is suggested to separate the spermatozoids from the vaginal epithelium cells--it has been used up to now in genetics alone. The method involves the available reagents and does not need any extra training. Its elaboration and introduction would resolve one of the most often-encountered issues set by the investigating office.